Ministry of Forests, Research Branch March 2002 ______

Annual Report - 2001

PROJECT NAME

Monitoring Restoration of Fire-Maintained Ecosystems in the Invermere Forest District

ORIGINATOR

Reg Newman (250) 371-3703 [email protected]

Craig DeMaere (250) 371-3704 [email protected]

PROJECT OBJECTIVES

The general goals of this monitoring project are to document the changes in understory plant community following thinning and prescribed burning of ingrown forests in the Invermere Forest District.

SUMMARY

Pre-harvest sampling for understory herbaceous plants and shrub cover, understory light, duff and fine fuel, and forage production were completed in 1999 at two sites. Subsequently, two blocks at Sheep Creek North were harvested in June 1999 and three blocks at Wolf Pasture were harvested during June-July 2000. All first-year post-harvest sampling was completed at Sheep Creek North in 2000. Only forage production sampling occurred at Wolf Pasture in 2000.

Sheep Creek North The thinning treatment removed an average of 68 m3/ha at Sheep Creek North leaving 59 m3/ha on site. Merchantable stem density decreased by 261 stems/ha, leaving 243 stems/ha on site. Understory light (measured as canopy openness) increased by 27% following the thinning treatment. After 1 year, understory plants have not responded to the increased light in the understory. Exposed soil was increased by 10% due to the harvesting activity.

Monitoring Ecosystem Restoration Annual Report – 2001 1 Wolf Pasture The thinning treatment removed an average of 48 m3/ha at Wolf Pasture, leaving 27 m3/ha on site. Merchantable stem density decreased by 513 stems/ha, leaving 192 stems/ha on site. Understory light and plant cover were not sampled for Wolf Pasture in 2000.

Light requirement for bunchgrass Bunchgrass is the dominant plant at canopy openness greater than 50% at Wolf Pasture (PPdh2). At this site, pinegrass declines at canopy openness levels greater then 30%. The relationship is not the same at Sheep Creek North (IDFdm2). Bunchgrass is never dominant over pinegrass at Sheep Creek North, but does decline in abundance at canopy openness greater than 55%. The composition of pinegrass and bunchgrass in the understory appears to be controlled by factors in addition to light. It may be that soil moisture is as important as light in determining the relative composition of pinegrass and bunchgrass in the Trench.

BACKGROUND

Dry forests in the Invermere Forest District have been highly altered by fire suppression, selective logging, Christmas tree production, and overgrazing. These activities have altered the landscape to the point that: 1) wildlife habitat for certain species has diminished; 2) forage production for domestic livestock and wild ungulates has been reduced; 3) timber quality is reduced; 4) insect and disease infestations have increased; and, 5) the risk of a stand initiating wild fire has increased.

The altered fire regime and its impact on natural resource values was recognized in the regional land use planning process (Kootenay-Boundary Land Use Plan) which led to the creation of the ecosystem restoration program. The overall goal of the ecosystem restoration program is to restore historic ecological conditions of forests and open ranges in the Rocky Mountain Trench, especially open forest and bunchgrass communities. In the Invermere Forest District, restoration of these altered ecosystems to open forest, and open range will be carried out using a three-phase rotational prescription of thinning and prescribed burning. An adaptive management project was initiated to monitor the efficacy of the planned restoration system. The information generated from the initial restoration work will be used to shape the restoration approach over the planned 60-year cycle of the restoration plan. This approach will increase the likelihood that the management goals of the restoration work will be met.

Monitoring Ecosystem Restoration Annual Report – 2001 2 TASKS COMPLETED

Wolf Pasture

Wolf Pasture is located in the southern part of the Premier Range Unit. The area is classified as PPdh2 (Kootenay Dry Hot Ponderosa Pine Variant). The dominant tree species in this stand is ponderosa pine.

Vegetation and light sample plots (macro-plots) were established in blocks 1, 2, and 3 in either Type 1 or 2 in 1999 (Table 1, Fig. 1). Macro-plot locations were chosen to match selected existing cruise plot centres. Wolf Pasture was thinned during June-July 2000. Macro-plots were re-established after the treatment and permanently located with metal pins. Macro-plot 4 (block 2) was discarded due to heavy disturbance from construction of a landing. Macro-plot 2 (block 1), and macro-plot 2 (block 2) had not yet received the thinning treatment when last checked. Macro-plot 2 (block 2) was burned slightly during an escaped prescribed fire from an adjacent block. An additional “open range” macro-plot was established and sampled at the west-end of the site because the original “open range” macro-plot could not be relocated. Two more macro-plots (controls) were established in 2000; both located on cruise plots in the same block as the originally installed control (Fig. 1).

Forage clipping was completed in September 2000.

Light and vegetation sampling occurred the week of June 2001. Cages were established in July 2001 and both uncaged and caged plots were clipped in late September 2001.

Table 1. Site characteristics.

Site Size Biogeoclimatic Timber Plots in timber (ha) classification types Type

Wolf Pasture 83.3 PPdh2 1 - PlPy(Fd)4205-12 13 2 - PyFdPl 4205-12 4

Sheep Creek 165.1 IDFdm2 3 - FdPlPy 42P3 10 9 - PyPlFdL 43M4 2 8 - PlPy 42M3 1

Monitoring Ecosystem Restoration Annual Report – 2001 3 Control Site

1010 12 7

13 2OR 2 2 9 9 8 8 6 6 7 7

New Open 3 3 Range No Logging 1OR1

Thrown out 9 9 8 8 7 7

2 2 4 4 6 6 7 7 8 8

1010 1212 9 9

Figure 1. Location of cruise plots used for sampling. Wolf Pasture

Monitoring Ecosystem Restoration Annual Report – 2001 4 Sheep Creek

Sheep Creek North-CP 162 is located on the North end of the Premier Unit. The area is typical of the IDFdm2 (Kootenay Dry Mild Interior Douglas-fir Variant). The dominant tree species in this stand is Douglas-fir.

Vegetation and light macro-plots were established in blocks 2 and 5, in Timber Types 3, 8 and 9 (Table 1, Fig. 2). Macro-plot locations were chosen to match selected existing cruise plot centres (Fig. 2). Sheep Creek North was thinned in June 1999. The thinning treatment was consistent throughout the entire block, however, thinning did not remove plot trees on two macro-plots (75 and 76 in block 2). Macro-plots were re-established in September 1999 and permanently located with metal pins. Plot 80 was discarded due to site factors.

All sampling was completed for 2000. Light and vegetation sampling occurred in June 2000. Cages were established in July 2000 and both uncaged and caged plots were clipped in late September 2000.

Monitoring Ecosystem Restoration Annual Report – 2001 5 52a52a

7070

60c60c 65 69 6969 7373

6868 7474 8080 Thrown out 7575

4545 4444 76 8585 No Logging in macro-plot 8686

Figure 2. Location of cruise plots used for sampling. Sheep Creek North

Monitoring Ecosystem Restoration Annual Report – 2001 6 METHODS

All understory sampling (macro-plots) occur on three 10 metre transects located within timber cruise plots. One transect is centred on the cruise plot centre while the other two transects are located 4 metres east and west of the cruise plot centre. All transects are oriented south to north with the 0 metre mark at the south end (Figure 3). In 2000, macro-plot sampling followed the original working plan design (Powell et al. 1999) except for a few modifications.

Cover Plant species cover and abundance were sampled on the outside transects using the Daubenmire canopy coverage method. The canopy coverage of all herbaceous vascular plant species and some physical characteristics is estimated within 20 x 50 cm quadrats. The canopy coverage of shrubs is estimated within larger 1 x 2 m quadrats. Vegetation was sampled every metre starting at the 0 metre mark. For 2000, the number of quadrats was increased from 10 to 20.

Light Diffuse light measurements using the LI-COR LAI-2000 Plant Canopy Analyzer were taken on the same transects as plant cover. Diffuse light measurements provide the “openness” of the tree canopy (also known as the canopy gap fraction). Light samples were taken at each a metre starting at the 1 metre mark (20 samples in total). All samples were taken facing north (away from the sun) with a 90° viewcap. The viewcap was used to minimize the sun’s influence, and isolate the gaps in the canopy better for a more accurate measurement. All light sampling occurred on evenly cloudy days, or at dusk.

Forage production Clipping methodology was changed slightly to incorporate 1-m² forage cages (Fig. 3). Two cages were installed on five macro-plots at each site. Cages were located at the start and end of the central transect. Four uncaged 0.5 m² plots were clipped at each macro-plot. Clipped material was sorted into bunchgrass, pinegrass, sedges, forbs. Shrubs were not clipped.

Monitoring Ecosystem Restoration Annual Report – 2001 7 N 10 10 ‘00 9 9 W E ‘01 8 8 S ‘02 ‘99‘03 7 7 Duff measurement ‘00 ‘01 locationLight measurement 6 6 Cruise Plot Centre location ‘02 ‘99‘03 5 5 Shrub cover ‘00 ‘01 frame (1 x 2 m) 4 Daubenmire canopy 4 cover frame (20 x 50 ‘02 ‘99‘03 Uncagedcm) Forage 3 3 ‘00 ‘01 ‘00 production plot (0.5 x 2 2 1 m) showing year of ‘02 ‘99‘03 clipping 1 1 Caged forage ‘00 ‘00 production plot, 2000 0 0 location Transect 1 Transect 2

Figure 3. Layout of a macroplot showing sampling locations and dimensions.

Monitoring Ecosystem Restoration Annual Report – 2001 8 RESULTS

Sheep Creek North

The thinning treatment removed an average of 68 m3/ha at Sheep Creek North leaving 59 m3/ha on site. Merchantable stem density decreased by 261 stems/ha, leaving 243 stems/ha on site (Table 2). As expected, individual macro-plots were not all thinned to the same extent. Volume remaining within macro-plots ranged from 0 to 142 m3/ha (Figure 4).

Table 2. Pre- and post-thinning stock and merchantable volume for Sheep Creek North.

Pre- P Post-treatment cruisetreat rm m Stems1 Volume C.V.3 aStems Volume C.V. 3 Stemsac Volume C.V. 3

Sheep Creek ? ? 503.6 126.8 50% 243.4 58.8 68% Type 3 ? 70 Type 8 ? 108 Type 9 ? 57 1All cruise plots from original cruise. 2Cruise plots corresponding to macro-plots. 3Coefficient of variation.

Understory light (measured as canopy openness) increased by 22% following the thinning treatment. Thinning introduced more light variability into the stand. The variability of canopy openness among macro-plots increased from 27% to 36% following thinning. Canopy openness now ranges from 22% to 76 % (Fig. 5).

The cover of shrubs at Sheep Creek North decreased (P  0.10) following thinning. Shrub cover in 2001 was 50% of the pre-thinned cover measured in 1999 (Fig. 6). Most of the decrease in total shrubs was due to the decrease in birch-leaved spirea (Spirea betulifolia), although decreases in kinnikinick (Arctostaphylos uva-ursii), saskatoon (Amelanchier alnifolia), regenerating Douglas-fir (Pseudotsuga menziesii), Soopolalie (Shepherdia canadensis), and bitterbrush (Purshia tridentata) also contributed. It is apparent that shrubs suffered physical damage during the disturbance caused by the thinning treatment. Shrubs may also be responding negatively to the changes in the understory micro-environment caused by opening the canopy. This is suggested by the continued decrease in cover in 2001.

No individual plant species showed significant (P  0.10) changes in cover, even though many showed a decreasing trend following thinning (Fig. 6). The cover

Monitoring Ecosystem Restoration Annual Report – 2001 9 values for many plant species are similar to pre-treatment measures, varying by less than 2%.

As expected, the cover of exposed soil increased (P  0.05) immediately following thinning. Exposed soil increased by 12 times when measured in 2000. Some amelioration of exposed soil occurred by 2001, probably due to colonization by plants. No increase in weeds occurred in response to the increased exposed soil.

Forage production (grasses and forbs only) at Sheep Creek was very low, averaging 93 kg/ha in 2000 and 2001 (Fig. 7). Sixty percent of this forage came from bunchgrasses and forbs while the remainder was primarily from pinegrass. No pre-thinning forage production data are available for comparison.

Monitoring Ecosystem Restoration Annual Report – 2001 10 a h / 3 m

e m u 350l o

V Pre-Treatment Post-Treatment 300

250

200

150

100

50

0 44 45 65 68 69 70 73 74 75 76 79 85 86 Macro-Plot

Figure 4. Volume measurement of cruise plots used as macro-plots at Sheep Creek North.

Monitoring Ecosystem Restoration Annual Report – 2001 11 (Fully Open) 100 90 Pre-treatment Post-treatment

) 80 % (

70 s s e 60 n n e

p 50 O

y 40 p o

n 30 a C 20 10 (No Light) 0 75 76 70 65 69 74 86 52A 85 79 68 60C 45 44 73 Macro-plot

Figure 5. Canopy openness before and after thinning treatments at Sheep Creek North.

Monitoring Ecosystem Restoration Annual Report – 2001 12 25 * 1999 2000 ) 20 2001 % (

r e v

o 15 c

y ** p o n

a 10 C

5

0

Plant species or group

Figure 6. Understory canopy cover of the dominant species at Sheep Creek North before (1999) and after thinning treatment (* significant at P  0.010; ** significant at P  0.05).

120

2000 2001 100 ) a h /

g 80 k (

n o i t c u d

o 60 r p

e g a r o F 40

20

0 Bunch grasses Forbs All forage plants Forage group

Figure 7. Understory forage production at Sheep Creek North after thinning treatment.

Monitoring Ecosystem Restoration Annual Report – 2001 13 Wolf Pasture

The thinning treatment removed an average of 48 m3/ha at Wolf Pasture, leaving 27 m3/ha on site. Merchantable stem density decreased by 513 stems/ha, leaving 192 stems/ha on site (Table 3). As expected, individual macro-plots were not all thinned to the same extent. Volume remaining within macro-plots ranged from 0 to 100 m3/ha (Figure 8).

Understory light and plant cover were sampled for Wolf Pasture in 2001. Understory light (measured as canopy openness) increased by an average of 30% following the thinning treatment. Canopy openness ranged from 14% to 47% before the thinning treatment. Canopy openness now ranges from 36% to 93% (Fig. 9).

The cover of shrubs at Wolf Pasture decreased (P  0.05) following thinning. Similar to the Sheep Creek North block, shrub cover in 2001 was 50% of the pre- thinned cover measured in 2000 (Fig. 10). Most of the decrease in total shrubs was due to the decreases in kinnikinick (Arctostaphylos uva-ursii), saskatoon (Amelanchier alnifolia), and bitterbrush (Purshia tridentata). It is apparent that shrubs suffered physical damage during the disturbance caused by the thinning treatment.

Grasses decreased by 62% (P  0.05) following thinning. Pinegrass (Calamagrostis rubescens) was the major species responsible for this decrease, although northwestern sedge (Carex concinnoides), and rough fescue (Festuca campestris) also contributed to the total decrease in grasses (Fig. 10).

Forbs decreased by 71% (P  0.10) following thinning, however, no individual forb species showed significant (P  0.10) changes in cover.

The cover of exposed soil increased by 7 times (P  0.05) following thinning. No increase in weeds occurred in response to the increased levls of exposed soil.

Forage production at Wolf Pasture decreased (P  0.05) one year following thinning. Forage production (grasses and forbs only) following thinning was only 50% of the pre-treatment levels (Fig. 11). Forage production average 99 kg/ha following thinning and 215 kg/ha before thinning. Before thinning 69% of the forage came from bunchgrasses and forbs while the remainder was primarily from pinegrass. After thinning 52% of the forage came from bunchgrasses and forbs while the remainder was primarily from pinegrass.

Monitoring Ecosystem Restoration Annual Report – 2001 14 Table 3. Pre and post thinning stock and merchantable volume for Wolf Pasture.

Pre- P Post-treatment cruisetreat rm m Stems1 Volume C.V.3 aStems Volume C.V. 3 Stemsac Volume C.V. 3

Wolf Pasture 442.8 68.01 69% 705.2 75.2 58% 192.0 27.0 101% Type 1 598.9 82.9 55% Type 2 241.9 52.1 43%

1All cruise plots from original cruise. 2Cruise plots corresponding to macroplots. 3Coefficient of variation.

Monitoring Ecosystem Restoration Annual Report – 2001 15 a h

/ 3

200m

e Pre-treatment

180m Post-treatment u l

160o V 140

120

100

80

60

40

20

0 1-2 1-3 1-6 1-7 1-8 1-9 1-10 2-2 2-4 2-6 2-7 2-8 2-9 2-12 3-7 3-8 3-9 3-10 Macro-plot

Figure 8. Volume on macro-plots at Wolf Pasture before and after the thinning treatment.

Monitoring Ecosystem Restoration Annual Report – 2001 16 Pre-treatment Post-treatment

100%

90%

80%

70% ) % ( 60% s s e n n e 50% p o y p o

n 40% a C

30%

20%

10%

0% 1-2 1-3 1-6 1-7 1-8 1-9 1-10 2-2 2-6 2-7 2-8 2-9 2-12 3-7 3-8 3-9 3-10 C-13 Macroplot

Figure 9. Canopy openness before and after thinning treatments at Wolf Pasture.

Monitoring Ecosystem Restoration Annual Report – 2001 17 40 Pre-treatment (2000) Post-treatment (2001) ** 35 ** ) 30 % (

r e v

o 25 ** c

y p

o 20 n ** a C 15 * 10 ** ** * 5 *

0

Plant species or group

Figure 10. Understory canopy cover of the dominant species at Wolf Pasture before and after thinning treatment (* significant at P  0.010; ** significant at P  0.05).

Monitoring Ecosystem Restoration Annual Report – 2001 18 250 1999 2000 2001

200 ) a h / g k (

n 150 o i t c u d o r p

e g a

r 100 o F

50

0 Bunch grasses Forbs All forage plants

Forage group

Figure 11. Understory forage production at Wolf Pasture before (1999) and after thinning treatment.

Monitoring Ecosystem Restoration Annual Report – 2001 19 Canopy openness requirement for bunchgrass

Pre-treatment plant cover data were used to determine if there was a natural threshold level of canopy openness at which bunchgrass would occur more frequently than pinegrass. This level could be used to set management prescriptions designed to encourage bunchgrass.

The frequency of pinegrass and bunchgrasses was compared to canopy openness using 1999 data from Wolf Pasture and Sheep Creek North. For this analysis, all bunchgrasses (Elymus spicatus, Festuca idahoensis, Festuca campestris, Koeleria macrantha, Stipa richardsonii, and Stipa comata) were lumped together because these grasses responded to light in a similar way.

At Wolf Pasture, pinegrass was found to increase in response to increasing light until about 30% canopy openness (Fig. 8). As light increased beyond 30% canopy openness, pinegrass decreased in frequency giving way to bunchgrass. Bunchgrass showed a similar increase in response to increasing canopy openness but did not decline after 30% openness. Bunchgrass continued to increase at all light levels sampled, and became more dominant than pinegrass at about 50% canopy openness. This relationship provides evidence that the canopy of stands to be restored should be opened up to 50% canopy openness, at a minimum.

The data from Sheep Creek North did not show the same relationship of pinegrass and bunchgrass to canopy openness. Pinegrass was found to increase until about 55% canopy openness (Fig. 9). Bunchgrass never gained dominance over pinegrass. In fact bunchgrass declined in frequency after about 40% canopy openness. This relationship suggests that bunchgrass will not increase in abundance, no matter how much the canopy is opened.

The difference in grass response at the two sites may relate to site differences. Sheep Creek North (IDFdm2) is more moist than Wolf Pasture (PPdh2). It appears that canopy openness alone cannot be used to predict the occurrence of pinegrass and bunchgrass. Factors such as soil moisture may be as important in determining the relative occurrence of the two grass types.

Monitoring Ecosystem Restoration Annual Report – 2001 20 1 0.9 0.8 0.7 Pinegrass 0.6 0.5

y 0.4 c n e

u 0.3 Bunchgrass q e r 0.2 F 0.1 0 0 10 20 30 40 50 60 70 (11) (47) (49) (57) (77) (27) (8) Light Class

Figure 8. Frequency of Key Grasses at Different Light Regimes at Wolf Pasture (PPdh2).

Monitoring Ecosystem Restoration Annual Report – 2001 21 1 0.9 0.8 Pinegrass 0.7 0.6 0.5 y c

n 0.4 e

u Bunchgrass q 0.3 e r F 0.2 0.1 0 0 10 20 30 40 50 60 70 (6) (47) (84) (63) (42) (13) (5) Light Class

Figure 9. Frequency of Key Grasses at Different Light Regimes at Sheep Creek (IDFdm2)

Monitoring Ecosystem Restoration Annual Report – 2001 22 Appendices

Plant species List

ScientificName Family

Forbs Achillea millefolium Asteraceae Agoseris glauca Asteraceae Allium cernuum Liliaceae Anemone multifida Ranunculaceae Anemone patens Ranunculaceae Antennaria microphylla Asteraceae Antennaria neglecta Asteraceae Antennaria umbrinella Asteraceae Antennaria unknown sp. Asteraceae Apocynum androsaemifolium Apocynaceae Arabis holboellii Brassicaceae Arnica cordifolia Asteraceae Aster conspicuus Asteraceae Aster foliaceus Asteraceae Aster sp. Asteraceae Astragalus miser Fabaceae Balsamorhiza sagittata Asteraceae Calochortus apiculatus Liliaceae Calochortus sp. Liliaceae Campanula rotundifolia Campanulaceae Castilleja thompsonii Scrophulariaceae Cerastium arvense Caryophyllaceae Cirsium arvense Asteraceae Collinsia parviflora Scrophulariaceae Collomia linearis Polemoniaceae Crepis atrabarba Asteraceae Draba sp. Brassicaceae Elymus repens Poaceae Epilobium angustifolium Onagraceae Erigeron filifolius Asteraceae Erigeron pumilus Asteraceae Fragaria virginiana Rosaceae Gaillardia aristata Asteraceae Geum triflorum Rosaceae Hedysarum sulphurescens Fabaceae Heterotheca villosa Asteraceae Heuchera cylindrica Saxifragaceae Hieracium albiflorum Asteraceae Hieracium scouleri Asteraceae

Monitoring Ecosystem Restoration Annual Report – 2001 23 Hieracium umbellatum Asteraceae Lathyrus nevadensis Fabaceae Lithospermum ruderale Boraginaceae Lomatium triternatum Apiaceae Lotus corniculatus Fabaceae Medicago lupulina Fabaceae Microsteris gracilis Polemoniaceae Oxytropis monticola Fabaceae Oxytropis sericea Fabaceae Penstemon confertus Scrophulariaceae Penstemon sp. Scrophulariaceae Phlox caespitosa Polemoniaceae Polygonum douglasii Polygonaceae Potentilla sp. Rosaceae Senecio canus Asteraceae Senecio streptanthifolius Asteraceae Solidago spathulata Asteraceae Stellaria nitens Caryophyllaceae Taraxacum officinale Asteraceae Tragopogon dubius Asteraceae Vicia americana Fabaceae Viola adunca Violaceae Zigadenus elegans Liliaceae Zygadenus sp. Liliaceae

Grass and grasslike Calamagrostis rubescens Poaceae Carex concinnoides Cyperaceae Carex sp. Cyperaceae Elymus glaucus Poaceae Elymus spicatus Poaceae Elymus trachycaulus Poaceae Festuca campestris Poaceae Festuca idahoensis Poaceae Festuca sp. Poaceae Koeleria macrantha Poaceae Poa compressa Poaceae Poa pratensis Poaceae Stipa comata Poaceae Stipa occidentalis Poaceae Stipa richardsonii Poaceae Stipa Sp. Poaceae

Shrubs and trees Amelanchier alnifolia Rosaceae Arctostaphylos uva-ursi Ericaceae

Monitoring Ecosystem Restoration Annual Report – 2001 24 Juniperus communis Cupressaceae Juniperus scopulorum Cupressaceae Mahonia aquifolium Berberidaceae Pinus contorta Pinaceae Pinus ponderosa Pinaceae Pseudotsuga menziesii Pinaceae Purshia tridentata Rosaceae Rosa acicularis Rosaceae Rosa gymnocarpa Rosaceae Rosa sp. Rosaceae Rosa woodsii Rosaceae Shepherdia canadensis Elaeagnaceae Spiraea betulifolia Rosaceae Symphoricarpos occidentalis Caprifoliaceae

Monitoring Ecosystem Restoration Annual Report – 2001 25